The relationship between flow proneness in everyday life and variations in the volume of gray matter in the dopaminergic system: A cross-sectional study

Flow Proneness - FP (i.e., dispositional tendency to experience flow) is subjectively different across individuals. An earlier study demonstrated that FP is correlated with the availability of dopamine receptors in the dorsal striatum including the caudate and the putamen. However, it remains unclear whether FP is associated with gray matter volume variations in the brain. The neuro-anatomical basis of FP has been investigated for the first time in the present study. We conducted a cross-sectional study with a high number of healthy employed Japanese adults (n = 680). We measured FP in different domains of everyday life (work, household maintenance, and leisure time) using a Japanese translation of a Swedish flow proneness questionnaire. We investigated gray matter volume using optimized voxel-based morphometry. As hypothesized, we found a significant region in the dorsal striatum. Our results indicate that an increase in gray matter volume in the right caudate is associated with an increase in overall FP in everyday life. However, the resulting correlation was relatively small (0.13). We discuss the potential reasons underlying these findings. Our findings might have further implications for flow research and well-being.